Background Anaphylaxis is increasing in young children. The aim of the present study was to analyze the clinical characteristics of anaphylaxis in Korean infants, with a focus on food triggers. Methods The study analyzed the medical records of infants aged 0 to 2 years old who had been diagnosed with anaphylaxis in 23 secondary or tertiary hospitals in Korea. Results We identified 363 cases of infantile anaphylaxis (66.9% male). Cutaneous symptoms were most prevalent (98.6%), followed by respiratory (83.2%), gastrointestinal (29.8%), and neurologic (11.6%) symptoms. Cardiovascular symptoms were noted in 7.7% of the cases. Most of the cases of anaphylaxis (338; 93.1%) were induced by foods. The most common trigger food was cow's milk and cow's milk products (43.8%), followed by hen's eggs (21.9%), walnuts (8.3%), wheat (7.7%), peanuts (4.8%), other nuts (3.0%), and fish (2.1%). In cow's milk-induced anaphylaxis cases, more than half the cases had cow's milk specific immunoglobulin E (sIgE) levels that were lower than the diagnostic decision points (DDPs), which is 5 kU A /L for those under the age of 1 and 15 kU A /L for those over the age of 1. In anaphylaxis induced by hen's egg, most of the cases (91.8%) had hen's egg sIgE levels that were higher than the DDP, which is 2 kU A /L for those under the age of 2 and 7 kU A /L for those over the age of 2. Of the infantile anaphylaxis cases, 46.8% had been treated with epinephrine, and 25.1% had been prescribed an epinephrine auto-injector. Conclusion Cow's milk is the most frequent trigger food of anaphylaxis in Korean infants. However, we found no significant correlation between the sIgE level and clinical severity. Education is required regarding the importance of epinephrine as the first line therapy for anaphylaxis and on properly prescribing epinephrine for infants with a history of anaphylaxis.

This study aimed to explore time trends in the prevalence of atopic dermatitis (AD) according to age in Korean children. We observed changes in the estimated annual prevalence of AD using data from the Korean National Health Insurance Service (NHIS) and Statistics Korea between 2003 and 2018. In each year, the highest prevalence was evident among children aged 12 to 23 months, and then the prevalence decreased with age. The annual prevalence of AD in Korean children under the age of 18 slightly increased from 4.0% in 2003 to 4.5% in 2018. During this period, the prevalence in children aged 6 to 18 years increased from 1.9% in 2003 to 3.1% in 2018, while that of infants aged less than 24 months substantially decreased. Among children who were born in 1991, 1997, 2000, 2003 and 2006, the slopes of decreasing trend lines over age 6 were similar. Comparing children born in 2009 and 2012 with those born before 2006, the more recent the birth year, the higher the prevalence of AD over age 6. In conclusion, time trends of the annual prevalence of AD in Korean children from 2003 through 2018 were different according to age group. These results suggest that AD development during infancy is decreasing whereas either a late-onset AD or early-onset, persistent phenotype is likely to increase. Different strategies according to age are required for more effective prevention and treatment of AD in Korean children.

Purpose This study aimed to evaluate the reliability and validity of the Korean version of the Food Allergy Quality of Life Questionnaire-Parent Form (K-FAQLQ-PF) and to identify clinical characteristics related to low quality of life (QoL) in Korean children with food allergy (FA). Methods Parents of 0–12-year-old patients with FA were enrolled. The English version of FAQLQ-PF was translated into Korean. Construct validation was confirmed by the Food Allergy Independent Measure-Parent Form (FAIM-PF) and the Child Health Questionnaire Parent Form 28 (CHQ-PF28). Logistic regression analyses were used to evaluate associations between potential risk factors and QoL outcomes. Results A total of 182 patients with a median age of 5.0 years were enrolled in the study. Cronbach’s α coefficient values indicating internal consistency were higher than 0.8. Intraclass correlation coefficient values for test-retest reliability were good for all age groups ( r > 0.6). Total K-FAQLQ-PF scores were positively correlated with the FAIM-PF ( r = 0.56, P < 0.05) and were negatively correlated with the parental impact-emotional domain in the CHQ-PF28 ( r = −0.44, P < 0.05). In multivariable logistic regression analysis, low QoL was significantly associated with female sex (adjusted odds ratio [aOR], 2.07; 95% confidence interval [CI], 1.03–4.18), age ≥ 5 years (aOR, 2.84; 95% CI, 1.31–6.16), FA diagnosis before the age of 3 years (aOR, 3.96; 95% CI, 1.13–13.93), the presence of atopic dermatitis (aOR, 2.21; 95% CI, 1.07–4.57), and residence in non-metropolitan areas (aOR, 3.44; 95% CI, 1.73–6.85). Conclusions According to parental perceptions, the K-FAQLQ-PF is a valid and reliable tool to assess psychosocial QoL in Korean children with FAs. Age, sex, residential area, and comorbid AD can affect the QoL of pediatric patients with FA.